I think the first step is to clean your computer, then we can come back to any lingering effects on Firefox. You can try these free programs to scan for malware. Since you are running a one-time "on demand" scan, they should not conflict with your existing antivirus software. Sometimes you need to restart Windows in order to flush programs currently in memory, however, I'd try the scans first. * [http://www.microsoft.com/security/scanner/default.aspx Microsoft Safety Scanner] * [http://www.malwarebytes.org/products/malwarebytes_free/ MalwareBytes' Anti-Malware] * [http://www.superantispyware.com/ SUPERAntiSpyware] * [http://www.bleepingcomputer.com/download/adwcleaner/ AdwCleaner] ''(ignore banner ads for other products)'' * [http://support.kaspersky.com/faq/?qid=208283363 TDSSKiller - AntiRootkit Utility] Further information can be found in the [[Troubleshoot Firefox issues caused by malware]] article. Were you able to get rid of the malware?